Decoupled spacer and plate and method of installing the same

ABSTRACT

Intervertebral spacer assemblies, systems, and methods thereof. A method of insertion includes inserting an intervertebral spacer and plate together using an insertion tool and, upon removal of the insertion tool, the intervertebral spacer and plate are no longer considered connected/coupled and act as separate components.

REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No. 17/683,248, filed Feb. 28, 2022, which is a continuation of U.S. application Ser. No. 16/292,546, filed Mar. 5, 2019, which is a divisional of U.S. application Ser. No. 15/867,073, filed Jan. 10, 2018, which is a continuation-in-part of U.S. application Ser. No. 15/661,027, filed Jul. 27, 2017, which is a continuation-in-part application of U.S. application Ser. No. 15/479,438, filed Apr. 5, 2017, all of which are hereby incorporated by reference in their entireties for all purposes.

BACKGROUND Field of the Invention

The present invention relates to bone fixation, and more specifically, to a method of installing an intervertebral spacer and plate.

Description of the Related Art

Various types of spacers can be used in spinal fusion procedures. A standalone spacer is one in which a spacer is attached to a plate. The plate is configured to receive one or more screws that secure the standalone spacer to one or more adjacent vertebrae. The combined spacer/plate structure is typically rigid, thereby reducing the flexibility of the patient at the implant site.

There exists a need for intervertebral spacer and plate assemblies that are inserted as a unit with an insertion tool, but are decoupled from each other when the insertion tool is removed. Further, methods of inserting the assemblies are also needed.

SUMMARY

To meet this and other needs, implants, systems and methods are provided to permit the insertion of a plate and spacer together or separately. If the plate and spacer are used together, a holder or group of holding instruments can be used to hold both the plate and spacer together during the insertion process. For example, the attachment of the plate, spacer and holder may be provided with a threaded rod without violating the graft space within the spacer. Additionally, embodiments may include a threaded rod and holder whose material and geometry lend to the rod curving within the holder, permitting the angular attachment of these components. Other embodiments of the plate, spacer, and instruments are described herein.

According to one embodiment, a method of installing an intervertebral spacer and plate assembly may include coupling an intervertebral spacer and plate to an insertion tool; delivering the coupled spacer and plate to a surgical site via the insertion tool, wherein the spacer and/or plate are received in an intervertebral disc space; inserting one or more bone screws into the plate to secure the plate to one or more adjacent vertebrae; and removing the insertion tool, such that the spacer is decoupled from the plate at the surgical site.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings in which like reference numerals identify similar or identical elements.

FIG. 1 is a perspective view of a spacer and plate assembly according to a first exemplary embodiment;

FIG. 2 is a perspective view of the spacer shown in FIG. 1 ;

FIGS. 3-6 show a top plan view, posterior elevational view, left lateral side elevational view, and right lateral side elevational view, respectively of the spacer shown in FIG. 2 ;

FIG. 7 is a perspective view of the plate shown in FIG. 1 ;

FIGS. 8-11 show a posterior elevational view, top plan view, left lateral side elevational view, and right lateral side elevational view, respectively, of the plate shown in FIG. 7 ;

FIGS. 12-14 show a top plan view, posterior elevational view, and right lateral side elevational view, respectively, of the assembly shown in FIG. 1 ;

FIG. 15 is a left lateral side elevational view of the spacer of FIG. 1 ;

FIG. 16 is a perspective view of the assembly components shown in FIG. 1 and an insertion tool for inserting the assembly;

FIG. 17 is a perspective view showing the plate of FIG. 7 having been inserted onto the insertion tool;

FIG. 18 is a perspective view showing the spacer and plate assembly of FIG. 1 having been inserted onto the insertion tool;

FIG. 19 is a top plan view, in section, of the plate and spacer of the assembly shown in FIG. 1 having been inserted onto the insertion tool;

FIG. 20 is a top plan view of a spacer and plate assembly according to a second exemplary embodiment;

FIGS. 21-24 are a posterior elevational view, left lateral side elevational view, exploded posterior perspective view, and exploded anterior perspective view, respectively, of the assembly shown in FIG. 20 ;

FIG. 25 is a top plan view, in section, of the plate of FIG. 20 and an insertion tool for inserting the plate;

FIG. 26 is a perspective view of the plate and insertion tool of FIG. 25 ;

FIG. 27 is a top plan view, in section, of the assembly of FIG. 20 and the insertion tool for inserting the assembly;

FIG. 28 is a perspective view of the assembly and insertion tool of FIG. 27 ;

FIG. 29 is a top plan view, in section, of a spacer block and the spacer and insertion tool of FIG. 27 ;

FIG. 30 is a perspective view of the spacer block, spacer, and insertion tool of FIG. 29 ;

FIG. 31 is a top plan view of a spacer and plate assembly according to a third exemplary embodiment;

FIGS. 32-35 are a posterior elevational view, left lateral side elevational view, exploded anterior perspective view, and exploded posterior perspective view, respectively, of the assembly shown in FIG. 31 ;

FIG. 36 is a top plan view, in section, of the plate of FIG. 31 and an insertion tool for inserting the assembly of FIG. 31 ;

FIG. 37 is a perspective view of the plate and insertion tool of FIG. 36 ;

FIG. 38 is a top plan view, in section, of the assembly of FIG. 31 and the insertion tool for inserting the assembly;

FIG. 39 is a perspective view of the assembly and insertion tool of FIG. 38 ;

FIG. 40 is a top plan view, in section, of a spacer block and the spacer and insertion tool of FIG. 38 ;

FIG. 41 is a perspective view of the spacer block, spacer, and insertion tool of FIG. 40 ;

FIG. 41A is an anterior perspective view of an alternative plate for use with the spacer shown in FIG. 20 ;

FIGS. 41B-41D are a left perspective view, left side elevational view, anterior side elevational view, respectively of the plate shown in FIG. 41A;

FIG. 42 is a top plan view of a spacer and plate assembly according to a fourth exemplary embodiment;

FIGS. 43-46 are a posterior elevational view, left lateral side elevational view, exploded anterior perspective view, and exploded posterior perspective view of the assembly shown in FIG. 42 ;

FIG. 47 is a top plan view, in section, of the plate of FIG. 42 and an insertion tool for inserting the assembly of FIG. 42 ;

FIG. 48 is a perspective view of the plate and insertion tool of FIG. 47 ;

FIG. 49 is a top plan view, in section, of the assembly of FIG. 42 and the insertion tool for inserting the assembly;

FIG. 50 is a perspective view of the assembly and insertion tool of FIG. 49 ;

FIG. 51 is a top plan view, in section, of a spacer block and the spacer and insertion tool of FIG. 49 ;

FIG. 52 is a perspective view of the spacer block, spacer, and insertion tool of FIG. 51 ;

FIG. 53 is a top plan view of a spacer and plate assembly according to a fifth exemplary embodiment;

FIGS. 54-57 are a posterior elevational view, left lateral side elevational view, exploded anterior perspective view, and exploded posterior perspective view, respectively, of the assembly shown in FIG. 53 ;

FIG. 58 is a top plan view, in section, of the assembly of FIG. 53 attached to an insertion tool for inserting the assembly of FIG. 53 ;

FIG. 59 is a perspective view of the assembly and insertion tool of FIG. 58 ;

FIG. 60 is a top plan view, in section, of the plate of FIG. 53 and the insertion tool for inserting the plate;

FIG. 61 is a perspective view of the plate and insertion tool of FIG. 60 ;

FIG. 62 is a top plan view, in section, of a spacer block and the spacer and insertion tool of FIG. 59 ;

FIG. 63 is a perspective view of the spacer block, spacer, and insertion tool of FIG. 62 ;

FIG. 64 is a top plan view of a spacer and plate assembly according to a sixth exemplary embodiment;

FIGS. 65-67 are a left lateral side elevational view, posterior elevational view, and exploded anterior perspective view, respectively, of the assembly of FIG. 64 ;

FIG. 68 is a perspective view of a spacer and plate assembly according to a seventh exemplary embodiment;

FIG. 69 is a perspective view of a spacer used with the assembly shown in FIG. 68 ;

FIG. 70 is a perspective view of a plate used with the assembly shown in FIG. 68 ;

FIGS. 71-74 are a top plan view, anterior elevational view, right side elevational view, and left side elevational view, respectively, of the spacer shown in FIG. 69 ;

FIGS. 75-78 are an anterior elevational view, top plan view, right side elevational view, and left side elevational view, respectively, of the plate shown in FIG. 70 ;

FIGS. 79-82 are a top plan view, anterior elevational view, right side elevational view, and left side elevational view, respectively, of the assembly shown in FIG. 68 ;

FIG. 83 is a perspective view of a spacer and plate assembly according to an eighth exemplary embodiment;

FIG. 84 is a perspective view of a spacer used with the assembly shown in FIG. 83 ;

FIG. 85 is a perspective view of a plate used with the assembly shown in FIG. 83 ;

FIGS. 86-89 are a top plan view, anterior elevational view, right side elevational view, and left side elevational view, respectively, of the spacer shown in FIG. 84 ;

FIGS. 90-93 is an anterior elevational view, a posterior elevational view, right side elevational view, and a top plan view of the plate shown in FIG. 85 ;

FIGS. 94-97 is a top plan view, anterior elevational view, right side elevational view, and left side elevational view of the assembly shown in FIG. 83 ;

FIG. 98 is a side elevational view, in section, of the assembly shown in FIG. 94 , taken along lines 98-98 of FIG. 94 ;

FIG. 99 is a perspective view of a spacer and plate assembly according to a ninth exemplary embodiment;

FIG. 100 is a perspective view of a spacer used with the assembly shown in FIG. 99 ;

FIG. 101 is a perspective view of a plate used with the assembly shown in FIG. 99 ;

FIGS. 102-105 is a perspective view, top plan view, anterior elevational view, and posterior elevational view of the spacer shown in FIG. 100 ;

FIGS. 106-109 is top plan view, perspective view, anterior elevational view, and posterior elevational view of the plate shown in FIG. 101 ;

FIGS. 110-113 is a top plan view, anterior elevational view, right side elevational view, and left side elevational view of the assembly shown in FIG. 99 ;

FIG. 114 is an anterior elevational view of a spacer and plate assembly according to a tenth exemplary embodiment;

FIGS. 115-116 is a top plan view and right side elevational view of the assembly shown in FIG. 114 ;

FIG. 117 is a top plan view of a spacer and plate assembly according to an eleventh exemplary embodiment;

FIG. 118 is a top plan view of a spacer and plate assembly according to a twelfth exemplary embodiment;

FIG. 119 is a top plan view of a spacer and plate assembly according to a thirteenth exemplary embodiment;

FIG. 120 is a top plan view of a spacer and plate assembly according to a fourteenth exemplary embodiment;

FIG. 121 is a top plan view of a spacer and plate assembly according to a fifteenth exemplary embodiment;

FIG. 122 is a top plan view of a spacer and plate assembly according to a sixteenth exemplary embodiment;

FIG. 123 is posterior side elevation view of a spacer according to a seventeenth exemplary embodiment;

FIG. 124 is an anterior side elevation view of the spacer shown in FIG. 123 ;

FIG. 125 is a top plan view of the spacer shown in FIG. 123 , with a plate and insertion device;

FIG. 126 is a top plan view of a spacer and plate assembly according to an eighteenth exemplary embodiment;

FIG. 127 is a posterior side elevation view of the assembly shown in FIG. 126 ;

FIG. 128 is a top plan view of a spacer and plate assembly according to a nineteenth exemplary embodiment;

FIG. 129 is a posterior side elevation view of the plate shown in FIG. 128 ;

FIG. 130 is a posterior side elevation view of the spacer of FIG. 128 ;

FIG. 131 is a top perspective view of a spacer and plate assembly according to a nineteenth embodiment;

FIGS. 132-134 is a top view, side view, and posterior view of the assembly shown in FIG. 131 ;

FIG. 135 is a posterior view of the spacer shown in FIG. 131 ;

FIG. 136 is a top perspective view of the assembly shown in FIG. 131 attached to an insertion tool;

FIGS. 137-139 is a top view, side view, and bottom view of the assembly shown in FIG. 131 attached to an insertion tool;

FIGS. 140A-140C illustrate the insertion tool being attached to the spacer and plate assembly in accordance with some embodiments;

FIG. 141 is a top perspective view of a spacer and plate assembly according to a twentieth embodiment;

FIG. 142-145 is a top view, side view, bottom view, posterior view of the assembly shown in FIG. 141 ;

FIGS. 146A-146C illustrate the spacer and plate assembly with the gripping features of the plate in a neutral position in accordance with some embodiments;

FIGS. 147A-147C illustrate the spacer and plate assembly with the gripping features of the plate in a compressed position in accordance with some embodiments.

FIG. 148 is a top perspective view of a spacer and plate assembly according to a twenty-first embodiment;

FIG. 149 is a posterior view of the assembly shown in FIG. 148 ;

FIG. 150 is a sectional view of the asse3mbly shown in FIG. 149 , taken along lines 150-150 of FIG. 149 ;

FIG. 151 is a posterior view of the spacer shown in FIG. 148 ;

FIG. 152 is a posterior view of the plate shown in FIG. 148 ;

FIG. 153 is a perspective view of the spacer and plate assembly of FIG. 148 , attached to a holder;

FIG. 154 is a top plan view of the spacer and plate assembly and the holder of FIG. 153 ;

FIG. 155 is a side elevational view of the spacer and plate assembly and the holder of FIG. 153 ;

FIG. 156 is a sectional view of the spacer and plate assembly and the holder of FIG. 155 , taken along lines 156-156 of FIG. 155 ;

FIG. 157 is a perspective view of the spacer and plate assembly and the holder of FIG. 153 , in a disassembled condition;

FIG. 158 is a perspective view of the spacer and plate assembly and the holder of FIG. 157 , with the shaft inserted into the holder;

FIG. 159 is a perspective view of the spacer and plate assembly and the holder of FIG. 158 , with the plate attached to the holder; and

FIG. 160 is a perspective view of the spacer and plate assembly and the holder of FIG. 159 , with the spacer attached to the holder.

DETAILED DESCRIPTION

In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The terminology includes the words specifically mentioned, derivatives thereof and words of similar import. The embodiments illustrated below are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention.

In performing spinal fusion procedures, a spacer can be inserted into a disc space. In some embodiments, a standalone spacer can be attached to a plate. The plate can receive one or more bone anchors or screws to attach to the plate to one or more adjacent vertebrae. The plate and spacer are often rigidly connected and are not decoupled from one another.

The present application includes spacer and plate assemblies that can be coupled via an insertion instrument upon delivery to a surgical site. In some embodiments, a surgical site can be at or near a disc space, as one skilled in the art will appreciate. The insertion instrument advantageously provides a single tool for delivering both the spacer and plate if desired. Once the spacer and plate are implanted at the surgical site, the insertion instrument can be removed. With the insertion instrument removed, the spacer and plate are considered decoupled from one another. By providing a spacer and plate that are independent and decoupled from one another, a surgeon advantageously has the option to implant both a plate and a spacer, a spacer by itself, or a plate by itself if desired.

The present disclosure provides embodiments of intervertebral spacers and plates that can be used to space and fixedly secure two adjacent vertebrae. According to one embodiment, shown in FIGS. 1-19 , an intervertebral spacer and plate assembly 100 (“assembly 100”) is provided. In an exemplary embodiment, assembly 100 can be used for cervical repair, although those skilled in the art will recognize that assembly 100 can be sized for thoracic or lumbar repair as well.

Assembly 100 is formed from two separate components, an intervertebral spacer 102 and a plate 104. In some embodiments, spacer 102 and plate 104 are not directly connected to each other, but are instead each separately coupled to an insertion tool 106, shown in FIGS. 16-19 .

Referring to FIGS. 1-6 , spacer 102 includes a body 108 having a superior surface 110 and an opposing inferior surface 112. Each of superior surface 110 and inferior surface 112 can have a plurality of protrusions or fixation elements 114 extending outwardly therefrom. While fixation elements 114 are shown as being generally pyramidal in shape, those skilled in the art will recognize that fixation elements 114 can be other shapes, such as ribbed, or other suitable shapes. Fixation elements 114 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 102 is inserted.

As shown in FIG. 2 , body 102 can have a generally U-shape, with generally parallel lateral sides 116, 118, connected to each other by an anterior portion 120. Lateral side 116 includes a convex arcuate posterior face 117 while lateral side 118 includes a convex arcuate posterior face 119. The space between lateral sides 116, 118 can optionally be filled with graft material. The advantage of a U-shaped body is that if a surgeon decides to use the spacer 102 on its own, it can be easily backfilled through the opening of the “U”. Referring to FIGS. 2-4 , superior surface 110 along lateral side 118 includes a cutout 111 that slopes inferiorly in an anterior-to posterior direction. Similarly, inferior surface 112 along lateral side 116 includes a cutout 113 that slopes superiorly in an anterior-to posterior direction. Cutouts 111, 113 allow for securing screws (not shown) to be inserted through plate 104, along cutouts 111, 113, respectively, and into adjacent vertebrae (not shown) without engaging spacer 102.

Lateral side 116 includes a tubular protrusion 122 extending in an anterior-posterior direction. Protrusion 122 has an internally threaded passage 124 that is sized to accept a portion of insertion tool 106 as will be explained in detail below. Passage 124 can have a closed anterior end 125.

Lateral side 118 includes an open slot 126 that extends in an anterior-posterior direction. An anterior end 128 of slot 126 extends medially inward and is sized to accept a portion of insertion tool 106 as will be explained in detail below.

Referring now to FIGS. 1 and 7-11 , plate 104 includes a body 130 having a superior surface 132 and an opposing inferior surface 134. In some embodiments, the plate 104 is sized and configured to be received within a disc space, while in other embodiments, at least a portion of the plate 104 is sized and configured to be received outside of a disc space. Each of superior surface 132 and inferior surface 134 can have a plurality of stabilizer elements 136 extending outwardly therefrom. In some embodiments, the stabilizer elements 136 can be for torsional stabilization. In an exemplary embodiment, one stabilizer element 136 is located along a central anterior-to-posterior axis, and a second stabilizer element 136 is located proximate to a lateral side of body 130. While stabilizer elements 136 are shown as being generally ribbed in shape, those skilled in the art will recognize that stabilizer elements 136 can be other shapes, such as pyramidal, or other suitable shapes. Stabilizer elements 136 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 102 is inserted.

As shown in FIG. 9 , body 130 can have a generally arcuate shape, with generally parallel lateral sides 138, 140. Each lateral side 138, 140 includes an anterior-to-posterior slot 142, 144, respectively. Slot 142 includes a superior surface 146 and a generally parallel inferior surface 148, while slot 144 includes a superior surface 150 and a generally parallel inferior surface 152. As shown in FIG. 13 , when plate 104 is aligned with spacer 102 for insertion, slot 142 is aligned with threaded passage 124 and slot 144 is aligned with open slot 126.

Body 130 includes a generally concave arcuate anterior face 156 that mates with convex arcuate faces 117, 119 of spacer 102 when plate 104 is located against spacer 102, as shown in FIG. 12 . Body 130 also includes a generally convex posterior face 158 that extends generally parallel to anterior face 156.

Through-holes 160, 162 extend through body 130 in a posterior-to-anterior direction. Through-holes 160, 162 are sized to allow a bone or securing screw (not shown) to be inserted therethrough to secure plate 104 to each of a superior vertebra (not shown) and an inferior vertebra (not shown), between which spacer 102 is being inserted. Through-hole 160 extends in a superior-to-inferior direction so that its screw engages and secures to the inferior vertebra, while through-hole 162 extends in an inferior-to-superior direction so that its screw engages and secures the superior vertebra.

A locking screw 164 is disposed between through-holes 160, 162. Locking screw 164 has a head 166 with diametrically opposed arcuate cutouts 168, 170 that are sized to allow the securing screws discussed above to be inserted into through-holes 160, 162. During insertion of assembly 100, locking screw 164 is in a configuration relative to plate 104 as shown in FIG. 8 . After the securing screws secure plate 104 to the superior and inferior vertebra, locking screw 164 is rotated, for example, about 90 degrees, so that head 166 extends over the securing screws, preventing the securing screws from inadvertently backing out.

FIGS. 1 and 12-15 show assembly 100. While plate 104 abuts spacer 102, plate 104 is not rigidly connected to spacer 102 in any way so that spacer 102 and plate 104 remain separate, independent components. During insertion via an insertion tool, the spacer 102 and plate 104 can both be coupled to the insertion tool. After insertion to a surgical site, the spacer 102 and plate 104 are decoupled from one another.

Referring now to FIGS. 16-19 , insertion tool 106 is used to insert spacer 102 and plate 104. Insertion tool 106 includes a distal end 170 having a first distal finger 172 and a second distal finger 174 that extends generally parallel to first distal finger 174. A gap 176 between fingers 172, 174 forms a generally U-shaped cavity 176 that is sized to accept plate 104 therein, as shown in FIG. 17 . This gap advantageously provides space for a surgeon to use a tool to insert one or more bone screws or anchors into the plate. First distal finger 172 includes a rod 178 having a threaded end 180 that threads into threaded passage 124 in tubular protrusion 122 on spacer 102, as shown in FIG. 19 . Rod 178 has a proximal end (not shown) that can be rotated by the surgeon to threadingly secure threaded end 180 into threaded passage 124.

Second distal finger 174 includes a prong 182 that extends generally toward first distal finger 172. Prong 182 is sized to fit into anterior end 128 of slot 126 on spacer 102.

While a single insertion tool 106 is shown, those skilled in the art will recognize that multiple insertion tools can be used. For example, a first insertion tool having only first distal finger 172 can be used in conjunction with a second insertion tool having only second distal finger 174.

According to one embodiment, a method of installing assembly 100, for example, at the site of two adjacent vertebrae (not shown), may include providing spacer 102, plate 104, and insertion tool 106 as a kit, as shown in FIG. 16 . Referring to FIG. 17 , plate 104 is connected to insertion tool 106 such that distal end 170 of insertion tool 106 extends distally of plate 104 (shown in FIG. 19 ). Plate 104 is connected to insertion tool 106 by attaching plate 104 to each of first finger 172 and second finger 174. First finger 172 is inserted into slot 142, while second finger 174 is inserted into second slot 144. Plate 104 is slid proximally onto each of first finger 172 and second finger 174, with plate 104 engaging each of first finger 172 and second finger 174 with an interference fit.

Next, as shown in FIGS. 18 and 19 , spacer 102 is attached to distal end 170 of insertion tool 106 by attaching spacer 102 to each of first finger 172 and second finger 174. Sequentially or simultaneously, first finger 172 is connected to spacer 102 by threading threaded end 180 that threads into threaded passage 124 in tubular protrusion 122 on spacer 102 and inserting prong 182 on second finger 174 into slot 126 on spacer 102 and sliding spacer 102 proximally until prong 182 engages anterior end 128 of slot 126, thereby frictionally engaging second finger 174 with spacer 102.

After assembly 100 is attached to insertion tool 106, spacer 102 is inserted between adjacent vertebrae. Gap 176 is sufficiently large between plate 104 and insertion tool 106 to allow securing devices, such as, for example, screws (not shown) to be inserted through through-holes 160, 162, and into inferior vertebra and superior vertebra, respectively, securing plate 104 to the vertebrae. After securing plate 104 to the vertebrae, insertion tool 106 is removed, leaving spacer 102 and plate 104, as separate components, in the patient's spinal column. While the plate 104 and spacer 102 are attached to the insertion tool 106 upon delivery to a surgical site, once the insertion tool 106 is removed, the plate 104 and spacer 102 can be viewed as decoupled or independent from one another.

An alternative embodiment of an intervertebral spacer and plate assembly 200 (“assembly 200”) is shown in FIGS. 20-28 . In an exemplary embodiment, assembly 200 can be used for lumbar repair, although those skilled in the art will recognize that assembly 200 can be sized for thoracic or cervical repair as well.

Assembly 200 is formed from two separate components, an intervertebral spacer 202 (“spacer 202”) and a plate 204 (“plate 204”). In some embodiments, spacer 202 and plate 204 are not connected to each other, but are instead each separately coupled to an insertion tool 206, as shown in FIGS. 25-28 .

Referring to FIGS. 20 and 22-24 , spacer 202 includes a body 208 having a superior surface 210 and an opposing inferior surface 212. Each of superior surface 210 and inferior surface 212 can have a plurality of protrusions or fixation elements 214 extending outwardly therefrom. While fixation elements 214 are shown as being generally pyramidal in shape, those skilled in the art will recognize that fixation elements 214 can be other shapes, such as ribbed, or other suitable shapes. Fixation elements 214 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 202 is inserted.

As shown in FIG. 20 , body 202 can have a generally oblong shape, with generally arcuate lateral sides 216, 218, connected to each other by an anterior portion 220 and a posterior portion 222. Lateral side 216 includes an indentation 217 while lateral side 218 includes a similar indentation 219. Indentations 217, 219 reduce the lateral length of posterior portion 222 relative to the remaining lateral length of spacer 202. A space 223 bounded by lateral sides 216, 218, anterior portion 220, and posterior portion 222 can optionally be filled with graft material.

Posterior portion 222 includes a first chamfered face 224 that extends in an inferior direction posteriorly from superior surface 210 and a second chamfered face 226 (shown in FIG. 23 ) that extends in a superior direction posteriorly from inferior surface 212. Chamfered faces 224, 226 allow for securing screws (not shown) to be inserted through plate 204, along chamfered faces 224, 226, respectively, and into adjacent vertebrae (not shown) without engaging spacer 202.

Posterior portion 222 also includes a smooth, anteriorly directed hole 228 proximate to lateral side 216. Hole 228 is sized to accept a non-threaded portion of insertion tool 206 as will be explained in detail below. Posterior portion 222 also includes a threaded, anteriorly directed hole 229 proximate to lateral side 218. Hole 229 is sized to accept a threaded portion of insertion tool 206 as will be explained in detail below.

Referring now to FIGS. 20-24 , plate 204 includes a body 230 having a superior surface 232 and an opposing inferior surface 234. Each of superior surface 232 and inferior surface 234 can have a plurality of stabilizer elements 236 extending outwardly therefrom. In some embodiments, the stabilizer elements 236 can be for torsional stabilization. In an exemplary embodiment, stabilizer elements 236 are located along fingers 238, 240 that extend anteriorly from plate 204. While stabilizer elements 236 are shown as being generally ribbed in shape, those skilled in the art will recognize that stabilizer elements 236 can be other shapes, such as pyramidal, or other suitable shapes. Stabilizer elements 236 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 202 is inserted.

As shown in FIG. 20 , body 230 can have a generally laterally elongate shape, with generally parallel lateral sides 242, 244. Fingers 238, 240 extend from lateral sides 242, 244, respectively. Fingers 238, 240 are sized to fit into indentations 217, 219 respectively, while a space between fingers 238, 340 is sized to allow posterior portion 222 of spacer 202 to be inserted therein.

Referring to FIG. 21 , through-holes 260, 262 extend through body 230 in a posterior-to-anterior direction. Through-holes 260, 262 are located on plate 204 to align with holes 228, 229 when plate 204 and spacer 202 are coupled as shown in FIG. 20 . Through-hole 260 can be smooth bored to allow for the passage of the non-threaded portion of insertion tool 206. Through-hole 262 can be smooth bored or threaded to allow for the insertion of the threaded portion of insertion tool 206.

Additional through-holes 264, 266, 268 are provided in plate 204 and are sized to allow a securing screw (not shown) to be inserted therethrough to secure plate 204 to each of a superior vertebra (not shown) and an inferior vertebra (not shown), between which spacer 202 is being inserted. Through-holes 264, 266 each extends in a superior-to-inferior direction so that their respective screw each engages and secures to the inferior vertebra, while through-hole 268 extends in an inferior-to-superior direction so that its screw engages and secures the superior vertebra.

Referring to FIG. 21 , locking screws 270, 272, 274 are each is disposed adjacent to a respective through-hole 264, 266, 268. Each locking screw 270, 272, 274 has a head 276, 278, 280 with an arcuate cutout 283, 285, 287, respectively, that is sized to allow the securing screws discussed above to be inserted into through-holes 264, 266, 268. During insertion of assembly 200, locking screws 270, 272, 274 are in a configuration relative to plate 204 as shown in FIG. 21 . After the securing screws secure plate 204 to the superior and inferior vertebra, locking screws 270, 272, 274 are rotated, for example, about 90 degrees, so that heads 276, 278, 280 each extends over its adjacent securing screws, preventing the securing screws from inadvertently backing out.

FIGS. 20-24, 27, and 28 show assembly 200. While plate 204 is butted up against spacer 202 to form a coupled construct, plate 204 is not connected to spacer 202 so that spacer 202 and plate 204 remain separate, independent components that can be implanted together or on their own as part of a fusion procedure.

Referring now to FIGS. 25-28 , insertion tool 206 is used to insert spacer 202 and plate 204. Insertion tool 206 includes a distal end 282 having a first distal finger 284 and a second distal finger 286 that extends generally parallel to first distal finger 282. First distal finger 282 is a generally smooth bore rod that is sized to pass through through-hole 260 in plate 204 and into hole 228 in spacer 202.

Second distal finger 286 includes a rod 288 having a threaded end 289 that threads into threaded through-hole 262 in plate 204, as shown in FIG. 25 , as well as into hole 229 in spacer, as shown in FIG. 27 . Rod 288 has a proximal end (not shown) that can be rotated by the surgeon to threadingly secure threaded end 289 into hole 229.

While a single insertion tool 206 is shown, those skilled in the art will recognize that multiple insertion tools can be used. For example, a first insertion tool having only first distal finger 282 can be used in conjunction with a second insertion tool having only second distal finger 286.

According to one embodiment, a method of installing assembly 200, for example, at the site of two adjacent vertebrae (not shown), may include providing spacer 202, plate 204, and insertion tool 206 as a kit, as shown in FIG. 28 .

As shown in FIGS. 23 and 24 , plate 204 is releasably engaged with spacer 202 in the absence of securing plate 204 to spacer 202 such that plate 204 engages spacer 202 between first finger 238 and second finger 240, as shown in FIG. 20 .

Next, insertion tool 206 is inserted through plate 204 and into spacer 202. Such insertion is performed by inserting insertion tool 206 through first through-hole 260 and second through-hole 262 and into holes 228, 229 of spacer 202. This is accomplished by threading threaded finger 286 of insertion tool 206 into plate 204 and into hole 229 in spacer 202, as well as inserting unthreaded finger 282 of insertion tool 206 through plate 204 and into hole 228 in spacer 202.

Next, spacer 202 is implanted between adjacent vertebrae. Insertion tool 206 is removed such that spacer 202 is separate from plate 204. Next, plate 204 is connected to the vertebrae.

Optionally, as shown in FIGS. 25 and 26 , insertion tool 206 can be releasably secured to only plate 204. Then, plate 204 can be coupled to spacer 202, after which time insertion tool 206 is then releasably secured to spacer 202.

A situation may arise wherein plate 204 is not required to secure spacer 202 between adjacent vertebrae; the compression of vertebrae toward each other is sufficient to maintain spacer 202 in place. In such a situation, plate 204 can be omitted. It is desired, however, to incorporate a substitute for plate 204 in order to provide desired spacing between plate 202 and insertion tool 206.

To achieve this spacing, as shown in FIGS. 29 and 30 , a spacer block 290 is provided. Spacer block 290 has substantially the same anterior-to-posterior width as plate 204, but without fingers 238, 240. Spacer block 290 includes a pair of unthreaded, smooth bore through-holes 292, 294 that align with holes 228, 229 of spacer 202 so that fingers 282, 286 of insertion tool 206 can be inserted therethrough and into hole 228, 229 of spacer 202 for insertion of spacer 202 between adjacent vertebrae (not shown).

An alternative embodiment of an intervertebral spacer and plate assembly 300 (“assembly 300”) is shown in FIGS. 31-39 . In an exemplary embodiment, assembly 300 can be used for lumbar repair, although those skilled in the art will recognize that assembly 300 can be sized for thoracic or cervical repair as well.

Assembly 300 is formed from two separate components, an intervertebral spacer 302 (“spacer 302”) and a plate 304 (“plate 304”). In some embodiments, spacer 302 and plate 304 are not connected to each other, but are instead each separately coupled to an insertion tool 306, as shown in FIGS. 38 and 39 .

Referring to FIGS. 31 and 34-35 , spacer 302 is similar to spacer 202, but, instead of a solid posterior portion 222, posterior portion 322 of spacer 302 includes a gap 325 between two medially directed ends 324, 326. Gap 325 allows for spacer 302 to flex after insertion, which may provide enhanced mobility for the patient.

Additionally, spacer 302 includes indentations 317, 319 that are larger than indentations 217, 219 on spacer 202. Similarly, fingers 338, 340 on plate 304 are wider than fingers 238, 240 on plate 204 to accommodate the larger indentations 317, 319.

Other aspects of spacer 302, plate 304, and insertion tool 306 are similar, if not identical, to corresponding aspects of spacer 202, plate 204, and insertion tool 206 as discussed above. Those aspects are identified with element numbers corresponding to spacer 202, plate 204, and insertion tool 206 with respect to spacer 302, plate 304, and insertion tool 306, respectively.

With respect to a spacer block 390 shown in FIGS. 40 and 41 , however, spacer block 390 includes fingers 396, 398 that are insertable into indentations 317, 319. Other aspects of spacer block 390 are similar, if not identical, to corresponding aspects of spacer block 290 as discussed above.

Instead of plate 304, an alternative plate 304′, shown in FIGS. 41A-41D can be provided. Plate 304′ is similar to plate 304, with the addition of a superior extension 393 on the posterior end 394 of plate 304′. Extension 393 increases the overall height of plate 304′ and allows plate 304′ to be shouldered onto the vertebral body during insertion. As shown in FIG. 41B, extension 393 can be straight. Alternatively, extension 393 can be angled in a posterior direction.

An alternative embodiment of an intervertebral spacer and plate assembly 400 (“assembly 400”) is shown in FIGS. 42-50 . In an exemplary embodiment, assembly 400 can be used for lumbar repair, although those skilled in the art will recognize that assembly 400 can be sized for thoracic or cervical repair as well.

Assembly 400 is formed from two separate components, an intervertebral spacer 402 (“spacer 402”) and a plate 404 (“plate 404”). In some embodiments, spacer 402 and plate 404 are not connected to each other, but are instead each separately coupled to an insertion tool 406, as shown in FIGS. 47 and 48 . Upon delivery to a surgical site, the spacer 402 and plate 404 can be decoupled from one another.

Referring to FIGS. 42-47 , spacer 402 is similar to spacer 302, but, instead of holes 260, 262 for insertion of insertion tool 306, lateral sides 416, 418 include a recess 460, 462, respectively. Recesses 460, 462 extend anteriorly from indentations 317, 319 toward anterior face 456. Each recess 460, 462 includes a plurality of superior-to-inferior extending slots 464. FIGS. 45 and 46 show two slots 464 in each recess 460, 462, although those skilled in the art will recognize that more or less than two slots 464 can be provided.

Additionally, fingers 338, 340 on plate 404 each include a recess 438, 440, respectively that extend in an anterior-to-posterior direction along the length of each respective finger 338, 340. Each recess 438, 440 includes a plurality of superior-to-inferior extending slots 464. FIGS. 45 and 46 show two slots 442 in each recess 438, 440, although those skilled in the art will recognize that more or less than two slots 442 can be provided.

Other aspects of spacer 402 and plate 404 are similar, if not identical, to corresponding aspects of spacer 302 and plate 304 as discussed above. Those aspects are identified with element numbers corresponding to spacer 302 and plate 304 with respect to spacer 402 and plate 404, respectively.

Insertion tool 406 is shown in FIGS. 47-52 . Insertion tool 406 includes a distal end 470 having a first distal finger 472 and a second distal finger 474 that extends generally parallel to first distal finger 474. A gap between fingers 472, 474 forms a generally U-shaped cavity 476 that is sized to accept plate 404 therein, as shown in FIGS. 47 and 48 . First distal finger 472 includes a plurality of protrusions 478 that fit into recess 460 and slots 464 on spacer 402 and recess 438 and slots 442 on plate 404. Similarly, second distal finger 474 includes a plurality of protrusions 480 that fit into recess 462 and slots 464 on spacer 402 and recess 440 and slots 442 on plate 404.

A proximal end (not shown) of insertion tool 406 can include a pivot connection such that the opening of insertion tool 406 at the proximal end splays first distal finger 472 away from second distal finger 474 to release spacer 402 and plate 404 so that spacer 402 and plate 404 are separated components.

Referring to FIGS. 51 and 52 , spacer block 490 includes slots 492 that receive protrusions 478, 480 on insertion tool 406. Other aspects of spacer block 490 are similar, if not identical, to corresponding aspects of spacer block 390 as discussed above.

An alternative embodiment of an intervertebral spacer and plate assembly 500 (“assembly 500”) is shown in FIGS. 53-63 . In an exemplary embodiment, assembly 500 can be used for lumbar repair, although those skilled in the art will recognize that assembly 500 can be sized for thoracic or cervical repair as well.

Assembly 500 is formed from two separate components, an intervertebral spacer 502 (“spacer 502”) and a plate 504 (“plate 504”). In some embodiments, spacer 502 and plate 504 are not connected to each other, but are instead each separately coupled to an insertion tool 506, as shown in FIGS. 58 and 59 .

Assembly 500 is similar to assembly 400 except that, instead of having gap 325 between two medially directed ends 324, 326, spacer 502 has a posterior portion 525 that extends fully between lateral sides 516, 518. Lateral sides 516, 518 include indentations 517, 519 that do not extend medially as far as indentations 317, 319 respectively, formed in spacer 402, as discussed above.

Additionally, referring to FIGS. 62 and 63 , a spacer block 590 includes slots 592 that receive protrusions 478, 480 on an insertion tool 4506.

An alternative embodiment of an intervertebral spacer and plate assembly 600 (“assembly 600”) is shown in FIGS. 64-67 . In an exemplary embodiment, assembly 600 can be used for lumbar repair, although those skilled in the art will recognize that assembly 600 can be sized for thoracic or cervical repair as well.

Assembly 600 is formed from two separate components, an intervertebral spacer 602 (“spacer 602”) and a plate 604 (“plate 604”). Plate 704 is shown in detail in FIGS. 75-78 . Plate 602 has a body 610 having a generally arcuate shape, with generally parallel lateral sides 612, 614. A posterior portion 625, respectively, of each lateral side 612, 614 includes an anterior-to-posterior recess 620, 622, respectively. Each recess 620, 622 includes a laterally projecting protrusion 624 having sloped superior and inferior sides (only one protrusion 624 is shown in FIG. 65 ). Each recess 620, 622 is in communication with a slot 628, 630, respectively that each extends medially. A medial portion 628, 629 of each lateral side 612, 614, respectively, include an oblique cutout 616, 618.

Plate 604 includes a body 605 having a generally laterally elongate shape, with generally parallel lateral sides 642, 644. Fingers 638, 640 extend from lateral sides 642, 644, respectively. Fingers 638, 640 are sized to fit into recesses 620, 622, respectively, in spacer 602. As shown in FIG. 65 , finger 638 includes a cutout 646 formed therein. Although not shown, finger 640 includes a corresponding cutout. An anterior end of each finger 638, 640 includes a medially extending prong 648, 650 that fits into a slot 628, 630, respectively. An anterior face 652 of body 605 also includes two spaced apart tangs 654, 656.

Referring to FIG. 66 , through-holes 664, 666, 668 are provided in plate 604 and are sized to allow a securing screw (not shown) to be inserted therethrough to secure plate 604 to each of a superior vertebra (not shown) and an inferior vertebra (not shown), between which spacer 602 is being inserted. Through-holes 664, 666 each extends in a superior-to-inferior direction so that their respective screw each engages and secures to the inferior vertebra, while through-hole 668 extends in an inferior-to-superior direction so that its screw engages and secures the superior vertebra.

Locking screws 670, 672 are each is disposed between respective through-holes 664, 666, 668. Each locking screw 670, 672 has a head 676 with a pair of arcuate cutouts 682, 684 that are sized to allow the securing screws discussed above to be inserted into through-holes 664, 666, 668. During insertion of assembly 600, locking screws 670, 672 are in a configuration relative to plate 604 as shown in FIG. 66 . After the securing screws secure plate 604 to the superior and inferior vertebra, locking screws 670, 672 are rotated, for example, about 90 degrees, so that heads 676, 678 each extends over its adjacent securing screws, preventing the securing screws from inadvertently backing out. In some embodiments, the locking screws 670, 672 (upon rotation) can abut a side of the securing screws to prevent inadvertent backing out.

Assembly 600 is fitted together by aligning fingers 638, 640 and prongs 648, 650 on plate 604 with recesses 620, 622 and slots 628, 630, respectively, on spacer 602, which also aligns lateral sides of tangs 654, 656 with cutout 616, 618, respectively. Plate 604 is slid down into spacer 602, locking fingers 638, 640 and prongs 648, 650 into recesses 620, 622 and slots 628, 630, respectively.

Additionally, protrusion 624 slides into cutout 646. Tangs 654, 656 engage cutouts 616, 618, respectively, stabilizing plate 604 with respect to spacer 602.

Assembly 600 is inserted between adjacent vertebrae as a unit, and, unlike other embodiments of the present invention, remain as a unit after implantation.

Another alternative embodiment of an intervertebral spacer and plate assembly 700 (“assembly 700”) is shown in FIGS. 68-82 . In an exemplary embodiment, assembly 700 can be used for cervical repair, although those skilled in the art will recognize that assembly 400 can be sized for thoracic or lumbar repair as well.

Assembly 700 is formed from two separate components, an intervertebral spacer 702 (“spacer 702”) and a plate 704 (“plate 704”). In some embodiments, spacer 702 and plate 704 are not connected to each other, but are instead each separately coupled to an insertion tool similar to insertion tool 406, shown in FIGS. 47 and 48 .

Referring to FIGS. 72-74 , spacer 702 is similar to spacer 402, but, instead of having gap 325 between two medially directed ends 324, 326, spacer 702 has a posterior portion 725 that extends fully between lateral sides 716, 718. Recesses 760, 762 extend anteriorly from posterior portion 725 toward anterior face 756. Each recess 760, 762 includes a plurality of superior-to-inferior extending slots 764. FIGS. 73 and 74 show two slots 764 in each recess 760, 762, respectively, although those skilled in the art will recognize that more or less than two slots 764 can be provided.

Posterior portion 725 includes cutouts 728, 730 to allow securing screws (not shown) to extend therethrough to secure plate 704 to adjacent vertebrae (not shown). When viewed from a posterior-to-anterior direction, a first cutout 728 is formed in a superior surface 710 and is defined by side walls 732, 734 and a bottom wall 736. As shown in FIG. 72 , side walls 732, 734 and bottom wall 736 extend at oblique angles relative to each other, although those skilled in the art will recognize that side walls 732, 734 can extend orthogonally to bottom wall 736.

Similarly, a second cutout 738 is formed in an inferior surface 712 and is defined by side walls 742, 744 and a top wall 746. As shown in FIG. 72 , side walls 742, 744 and top wall 746 extend at oblique angles relative to each other, although those skilled in the art will recognize that side walls 742, 744 can extend orthogonally to top wall 746.

Plate 704 is shown in detail in FIGS. 75-78 . Plate 704 has a body 750 having a generally arcuate shape, with generally parallel lateral sides 752, 754. Each lateral side 752, 754 includes an anterior-to-posterior recess 776, 778, respectively. Each recess 776, 778 is in communication with a slot 760, 762 in spacer 702.

Plate 704 also includes through-openings 782, 784 for securing screws (not shown) that are used to secure plate 704 to adjacent vertebrae (not shown). A locking screw 786 can be rotated, for example, about 90 degrees after the securing screws have been inserted to keep the securing screws from backing out after insertion. When plate 704 is aligned with spacer 702 as shown in FIGS. 79-82 , through-opening 782 is aligned with first cutout 728 in spacer 702 and through-opening 784 is aligned with second cutout 730 in spacer 702 so that the securing screws can pass over or under spacer 702 and into their respective vertebrae.

Also, as shown in FIGS. 81 and 82 , when plate 704 is aligned with spacer 702 for insertion, recess 776 is aligned with recess 760 and recess 778 is aligned with recess 762 so that an insertion tool, similar to insertion tool 406, can extend through plate 704 and grip spacer 702 for insertion.

The insertion procedure for assembly 700 can be similar to that as is described above for assembly 400. However, instead of insertion tool 406 having protrusions that engage plate 704, such protrusions can be omitted and assembly 700 can rely on friction between plate 704 and insertion tool 406, as well as between implant 702 and insertion tool 406.

An alternative embodiment of an intervertebral spacer and plate assembly 800 (“assembly 800”) is shown in FIGS. 83-98 . In an exemplary embodiment, assembly 800 can be used for cervical repair, although those skilled in the art will recognize that assembly 800 can be sized for thoracic or lumbar repair as well.

Assembly 800 is formed from two separate components, an intervertebral spacer 802 (“spacer 802”) and a plate 804 (“plate 804”). In some embodiments, spacer 802 and plate 804 are not connected to each other, but instead merely engage each other.

Referring to FIGS. 84 and 86-89 , spacer 802 includes a body 808 having a superior surface 810 and an opposing inferior surface 812. Each of superior surface 810 and inferior surface 812 can have a plurality of fixation elements 814 extending outwardly therefrom. While fixation elements 814 are shown as being generally pyramidal in shape, those skilled in the art will recognize that fixation elements 814 can be other shapes, such as ribbed, or other suitable shapes. Fixation elements 814 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 802 is inserted.

As shown in FIG. 20 , body 802 can have a generally oblong shape, with generally linear lateral sides 816, 818, connected to each other by an anterior portion 820 and a posterior portion 822, with a generally isosceles trapezoid interior space 823 defined therebetween that can optionally be filled with graft material.

Posterior portion 822 includes an arcuate face 824 that extends between lateral sides 816, 818. A rounded protrusion 826 extends posteriorly from posterior portion 822. A pair of insertion tool engagement holes 828, 829 are each located on opposing sides of protrusion 826. Holes 828, 829 can be threaded or unthreaded, and can be through-holes or blind holes. Holes 828, 829 are sized to accept arms of an insertion tool (not shown) for insertion of assembly 800.

Referring now to FIGS. 85 and 90-93 , plate 804 includes a body 830 having an anterior surface 832 and an opposing posterior surface 834. Referring to FIGS. 90 and 91 , plate 804 can have a generally “X” shape, with left and right superior arms 836, 838, respectively, and left and right inferior arms 840, 842, respectively. Superior arms 836, 838 include through-openings 844, 846 that are angled in a superior direction to allow screws (not shown) to be inserted therethrough to secure plate 804 to a superior vertebra (not shown). Similarly, inferior arms 840, 842 include through-openings 848, 850 that are angled in an inferior direction to allow securing screws (not shown) to be inserted therethrough to secure plate 804 to an inferior vertebra (not shown).

Referring to FIG. 90 , locking screws 852, 854, 856, 858 are each disposed adjacent to a respective through-opening 844, 846, 848, 850. Each locking screw 852, 854, 856, 858 has a head 860 with an arcuate cutout 862, respectively, that is sized to allow the securing screws discussed above to be inserted into through-openings 844, 846, 848, 850. During insertion of assembly 800, locking screws 852, 854, 856, 858 are in a configuration relative to plate 804 as shown in FIG. 95 . After the securing screws secure plate 804 to the superior and inferior vertebra, locking screws 852, 854, 856, 858 are rotated, for example, about 90 degrees, so that heads 860 each extends over its adjacent securing screws, preventing the securing screws from inadvertently backing out.

Plate 804 also includes a centrally located posterior recess 870. As shown in FIG. 90 , recess 870 can be generally oblong in shape, although those skilled in the art will recognize that recess 870 can be other shapes. Recess 870 accepts a prong on an insertion device (not shown) for insertion of assembly 800.

Referring to FIG. 91 , anterior surface 8732 of plate 804 includes a centrally located concave recess 874 that accepts protrusion 826, as shown in FIG. 98 . Protrusion 826 rides within recess 874, forming an articulating joint that allows plate 804 to pivot relative to body 802, providing some flexibility for the patient after assembly 800 is implanted.

FIGS. 83 and 95-98 show assembly 800. While plate 804 is butted up against spacer 802 to form a coupled construct, plate 804 is not rigidly connected to spacer 802 so that spacer 802 and plate 804 remain separate, independent components throughout insertion and after insertion into the patient.

An alternative embodiment of an intervertebral spacer and plate assembly 900 (“assembly 900”) is shown in FIGS. 99-113 . In an exemplary embodiment, assembly 900 can be used for cervical repair, although those skilled in the art will recognize that assembly 900 can be sized for thoracic or lumbar repair as well.

Assembly 900 is formed from two separate components, an intervertebral spacer 902 and a plate 904. Spacer 902 and plate 904 are never connected to each other, but instead merely engage each other.

Referring to FIGS. 99 and 102-105 , spacer 902 includes a body 908 having a superior surface 910 and an opposing inferior surface 912. Each of superior surface 910 and inferior surface 912 can have a plurality of fixation elements 914 extending outwardly therefrom. While fixation elements 914 are shown as being generally pyramidal in shape, those skilled in the art will recognize that fixation elements 914 can be other shapes, such as ribbed, or other suitable shapes. Fixation elements 914 are used to bite into a grip each of adjacent vertebrae (not shown) between which spacer 902 is inserted.

As shown in FIG. 103 , body 902 can have a generally oblong shape, with generally linear lateral sides 916, 918, connected to each other by an anterior portion 920 and a posterior portion 922, with a generally isosceles trapezoid interior space 923 defined therebetween that can optionally be filled with graft material.

Posterior portion 922 includes an arcuate face 924 that extends between lateral sides 916, 918. A generally centrally located insertion tool engagement hole 928 extends through posterior portion 922. Hole 928 can be threaded, as shown in FIG. 100 , or unthreaded. Hole 928 is sized to an insertion tool (not shown) for insertion of assembly 900.

A pair of plate engagement slots 931, 932 are each located on opposing sides of hole 928. Slots 931, 932 are blind holes and are generally rectangular in shape, with rounded corners. Slots 931, 932 are sized to accept posterior protrusions from plate 904, as is discussed below.

Referring now to FIGS. 101 and 106-109 , plate 904 includes a body 930 having an anterior surface 933 and an opposing posterior surface 934. Referring to FIGS. 108 and 109 and 91 plate can have a generally “rhomboid” shape, with a right superior arm 936 and a left inferior arm 940. Superior arm 936 includes a through-opening 944 that is angled in a superior direction to allow a screw (not shown) to be inserted therethrough to secure plate 904 to a superior vertebra (not shown). Similarly, inferior arm 940 includes a through-opening 948 that is angled in an inferior direction to allow a securing screw (not shown) to be inserted therethrough to secure plate 904 to an inferior vertebra (not shown).

Referring to FIG. 108 , locking screws 952, 954 are each disposed adjacent to a respective through-opening 944, 948. Each locking screw 952, 954 has a head 960 with an arcuate cutout 962, respectively, that is sized to allow the securing screws discussed above to be inserted into through-openings 944, 948. During insertion of assembly 900, locking screws 952, 954 are in a configuration relative to plate 904 as shown in FIG. 108 . After the securing screws secure plate 904 to the superior and inferior vertebra, locking screws 952, 954 are rotated, for example, about 90 degrees, so that heads 960 each extends over its adjacent securing screws, preventing the securing screws from inadvertently backing out.

Plate 904 also includes a centrally located through-opening 970. As shown in FIG. 108 , through-opening 970 can be generally circular in shape, although those skilled in the art will recognize that through-opening 970 can be other shapes. Through-opening 970 is unthreaded and allows an insertion device (not shown) to pass therethrough for engagement with hole 928 in spacer 902 for insertion of assembly 900.

Referring still to FIG. 108 , a posterior surface 972 of plate 904 includes a pair of diametrically opposed slots 974, 976 that extend at an oblique angle away from through-opening 970. Slots 974, 976 accept a prong of an insertion instrument (not shown) during implantation of assembly 900, allowing the insertion instrument to be placed into slots 974, 976 so that plate 904 is held rigidly on the insertion instrument without being able to rotate.

Referring now to FIGS. 106, 107, and 109 , an anterior surface 980 of plate 904 includes a pair of diametrically opposed protrusions 982, 984 that are sized and located to fit into plate engagement slots 931, 932. A posterior end of locking screws 952, 954 also extends outwardly from plate engagement slots 931, 932 as well.

FIGS. 99 and 110-113 show assembly 900. While plate 904 is butted up against spacer 902 to form a coupled construct, plate 904 is not connected to spacer 902 so that spacer 902 and plate 904 remain separate components throughout insertion and after insertion into the patient.

FIGS. 114-116 show an alternative plate 1004 that can be used with spacer 902 to form an assembly 1000. Plate 1004 has a generally rectangular shape with a centrally located through-opening 1070. As shown in FIG. 114 , through-opening 1070 can be generally circular in shape, although those skilled in the art will recognize that through-opening 1070 can be other shapes. Through-opening 1070 is unthreaded and allows an insertion device (not shown) to pass therethrough for engagement with hole 928 in spacer 902 for insertion of assembly 1000.

Plate 1004 has left and right superior through-openings 1044, 1046 that are angled in a superior direction to allow screws (not shown) to be inserted therethrough to secure plate 1004 to a superior vertebra (not shown). Similarly, plate 1004 has left and right inferior through-openings 1048, 1050 that are angled in an inferior direction to allow securing screws (not shown) to be inserted therethrough to secure plate 1004 to an inferior vertebra (not shown).

Locking screws 1052, 1054, 1056, 1058 are each disposed adjacent to a respective through-opening 1044, 1046, 1048, 1050. Each locking screw 1052, 1054, 1056, 1058 has a head 1060 with an arcuate cutout 1062, respectively, that is sized to allow the securing screws discussed above to be inserted into through-openings 1044, 1046, 1048, 1050. During insertion of assembly 1000, locking screws 1052, 1054, 1056, 1058 are in a configuration relative to plate 1004 as shown in FIG. 114 . After the securing screws secure plate 904 to the superior and inferior vertebra, locking screws 1052, 1054, 1056, 1058 are rotated, for example, about 90 degrees, so that heads 1060 each extends over its adjacent securing screws, preventing the securing screws from inadvertently backing out.

A posterior surface 1072 of plate 1004 also includes a pair of superior and inferior slots 1074, 1076 on opposing sides of through-opening 1070. Slots 1074, 1076 accept a prong of an insertion instrument (not shown) during implantation of assembly 1000, allowing the insertion instrument to be placed into slots 1074, 1076 so that plate 1004 is held rigidly on the insertion instrument without being able to rotate.

Referring now to FIG. 117 , an alternative embodiment of an intervertebral spacer and plate assembly 1100 (“assembly 1100”) is shown. Assembly 1100 includes a spacer 1102 and a plate 1104.

Plate 1102 has a body 1108 that includes a posterior surface 1110. Posterior surface 1110 includes a central through-opening 1112 that is sized to accept an insertion instrument 1106. Through-opening 1112 is threaded to match threads 1114 on a distal end 1116 of insertion instrument 1106. Posterior surface 1110 also includes a pair of concave recesses 1120, 1122, one on either side of through-opening 1112.

Plate 1104 has a body 1130 that includes an anterior surface 1132 for mating with posterior surface 1110 of spacer 1102. Body 1130 includes a through-opening 1134 that extends posteriorly-to-anteriorly through the center of body 1130. Through-opening 1134 has a larger diameter than through-opening 1112 in spacer 1102 to allow distal end 1116 of insertion instrument 1106 to pass therethrough.

Anterior surface 1132 of body 1130 also includes a pair of convex protrusions 1140, 1142, one on either side of through-opening 1134 that extend into recesses 1120, 1122, respectively, when plate 1104 is butted against spacer 1102, forming a solid construct.

Referring now to FIG. 118 , an alternative embodiment of an intervertebral spacer and plate assembly 1200 (“assembly 1200”) is shown. Assembly 1200 includes a spacer 1202 and a plate 1204.

Plate 1202 has a body 1208 that includes a posterior surface 1210. Posterior surface 1210 includes a central recess 1212. Posterior surface 1210 also includes a pair of threaded recesses 1220, 1222, one on either side of central recess 1212.

Plate 1204 includes a body 1230 having an anterior surface 1232. A protrusion 1234 extends anteriorly from anterior surface 1232 and is sized to fit into central recess 1212. Body 1230 also includes a pair of lateral through-holes 1236, 1238 that extend through body 1230 and align with threaded recesses 1220, 1222 when protrusion 1234 is inserted into central recess 1212.

To insert assembly 1200 into a patient, an insertion instrument (not shown) having two prongs is inserted through through-holes 1236, 1238 in plate 1204 and threaded into threaded recesses 1220, 1222 in plate 1204. Assembly 1200 is inserted into plate 1204 is secured to a patient, then the insertion tool is unthreaded from threaded recesses 1220, 1222 and removed from assembly 1200.

Referring now to FIG. 119 , an alternative embodiment of an intervertebral spacer and plate assembly 1300 (“assembly 1300”) is shown. Assembly 1300 includes a spacer 1302 and a plate 1304. Spacer 1302 includes a body 1308 having a central void 1309 formed therein. A posterior side 1310 of spacer 1302 includes a pair of through-passages 1312, 1314 into void 1309.

Plate 1304 includes a pair of fingers 1320, 1322, each of which extends into one of through-passages 1312, 1314 and into void 1309. When two prongs of an insertion device (not shown) are inserted into through-passages 1312, 1314, fingers 1320, 1322 splay open, temporarily securing plate 1304 to spacer 1302 for insertion. After insertion, when the insertion device is removed, fingers “un-splay” so that plate 1304 is no longer secured to spacer 1302 and spacer 1302 and plate 1304 are two separate entities.

Referring now to FIG. 119 , an alternative embodiment of an intervertebral spacer and plate assembly 1300 (“assembly 1300”) is shown. Assembly 1300 includes a spacer 1302 and a plate 1304. Spacer 1302 includes a body 1308 having a central void 1309 formed therein. A posterior side 1310 of spacer 1302 includes a pair of through-passages 1312, 1314 into void 1309.

Plate 1304 includes a pair of fingers 1320, 1322, each of which extends into one of through-passages 1312, 1314 and into void 1309. When two prongs of an insertion device (not shown) are inserted into through-passages 1312, 1314, fingers 1320, 1322 splay open, temporarily securing plate 1304 to spacer 1302 for insertion. After insertion, when the insertion device is removed, fingers “un-splay” so that plate 1304 is no longer secured to spacer 1302 and spacer 1302 and plate 1304 are two separate entities.

Referring now to FIG. 120 , an alternative embodiment of an intervertebral spacer and plate assembly 1400 (“assembly 1400”) is shown. Assembly 1400 includes a spacer 1402 and a plate 1404. Spacer 1402 includes a body 1408. A posterior side 1410 of spacer 1302 includes a pair of blind passages 1412, 1414 extending into body 1408. Each of blind passages 1412, 1414 widens to a receiving portion 1416, 1418, respectively, in a posterior-to-anterior direction.

Plate 1404 includes a pair of through-passages 1420, 1422 extending parallel to each other in a posterior-to-anterior direction such that, when plate 1404 is aligned with spacer 1402, passage 1420 aligns with passage 1412 and passage 1422 aligns with passage 1414.

An insertion device 1406 includes two parallel hollow prongs 1430, 1432. Each prong 1430, 1432 is split posteriorly into two half portions 1430 a, 1430 b and 1432 a, 1432 b, each portion 1430 a, 1430 b, 1432 a, 1432 b having a lip.

When prongs 1430, 1432 of insertion device 1406 are inserted through through-passages 1420, 1422 and into blind passages 1412, 1414, respectively, and rods (not shown) are inserted through prongs 1430, 1432, prong half portions 1430 a, 1430 b and 1432 a, 1432 b splay apart so that the lips on prongs 1430, 1432 splay open and are retained within receiving portions 1416, 1418, respectively, temporarily securing plate 1404 to spacer 1402 for insertion. After insertion, when the insertion device is removed, fingers “un-splay” so that plate 1404 is no longer secured to spacer 1402 and spacer 1402 and plate 1404 are two separate entities.

Referring now to FIG. 121 , an alternative embodiment of an intervertebral spacer and plate assembly 1500 (“assembly 1500”) is shown. Assembly 1500 includes a spacer 1502 and a plate 1504. Spacer 1502 includes a body 1508 having a central void 1509 formed therein. A posterior side 1510 of spacer 1502 includes a pair of through-passages 1512, 1514 into void 1509.

Plate 1504 includes parallel through-passages 1516, 1518 extending parallel to each other in a posterior-to-anterior direction such that, when plate 1504 is aligned with spacer 1502, passage 1516 aligns with passage 1412 and passage 14221518 aligns with passage 1514.

Insertion device 1506 includes a pair of fingers 1520, 1522, each of which extends through one of through-passages 1516, 1518 and one of through-passages 1512, 1514 and into void 1509. Each finger 1520, 1522 includes a laterally extending lip 1524, 1526, respectively.

When two prongs of an insertion device (not shown) are inserted into through-passages 1516, 1518 and 1512, 1514, with the prongs on medial sides of each of fingers 1520, 1522, fingers 1520, 1522 are biased laterally so that lips 1524, 1526 engage the posterior wall of void 1509, temporarily securing plate 1504 to spacer 1502 for insertion. After insertion, when the insertion device 1506 is removed, fingers 1520, 1522 bias back toward each other so that plate 1504 is no longer secured to spacer 1502 and spacer 1502 and plate 1504 are two separate entities.

Referring now to FIG. 122 , an alternative embodiment of an intervertebral spacer and plate assembly 1600 (“assembly 1600”) is shown. Assembly 1600 includes a spacer 1602 and a plate 1604. Spacer 1602 includes a body 1608. A posterior side 1610 of spacer 1602 includes a blind slot 1612 extending into body 1608. Slot 1612 includes lateral sidewalls 1614, 1616.

Plate 1604 includes a tab 1620 sized to fit into slot 1612 with lateral space on either side of tab 1620 to accommodate fingers 1622, 1624. Biased fingers 1622, 1624 are pivotally connected to spacer 1602 with anterior ends 1626, 1628 having a plurality of laterally extending fingers 1630. Posterior ends 1632, 1634 of fingers 1622, 1624 are engageable by an insertion device (not shown)

During insertion, fingers 1622, 1624 are against lateral sidewalls 1614, 1616 of slot 1612 so that plate 1604 is engaged with spacer 1602. Fingers 1630 compress toward their respective fingers 1622, 1624, wedging plate 1604 into spacer 1602. After assembly 1600 is inserted, the insertion device is removed, allowing fingers 1622, 1624 to bias away from sidewalls 1614, 1616, respectively, releasing spacer 1602 from plate 1604.

Referring now to FIGS. 123-125 , an alternative embodiment of an intervertebral spacer and plate assembly 1700 (“assembly 1700”) is shown. Assembly 1700 includes a spacer 1702 and a plate 1704. Spacer 1702 includes a body 1708 having a central void 1709 formed therein. A superior surface 1710 of spacer 1702 includes a central slot 1712 extending along a posterior surface 1714 to void 1709. Similarly, an inferior surface 1720 includes a corresponding slot 1722.

Referring to FIG. 123 , plate 1704 includes a slot 1730 extending along a top surface 1732 thereof and a slot 1734 extending along a bottom surface 1736 thereof. Plate 1704 includes a pair of screw opening 1740, 1742 and a centrally located blocking screw 1744. An alternative embodiment of a plate 1704′, shown in FIG. 124 , uses multiple blocking screws 1744′, 1746′, each for an individual screw opening 1740′, 1742′, with locking screws 1744′, 1746′ disposed laterally away from a center of plate 1704′ to allow plate 1704′ to be thinner than plate 1704 and still be able to secure screws (not shown) in screw openings 1740′, 1742′.

FIG. 125 shows in insertion device 1706 gripping both spacer 1702 and either plate 1704 or plate 1704′. Insertion device 1706 extends through slots 1730, 1712 and slots 1734, 1722, securing spacer 1702 and plate 1704, 1704′ to securing device 1706. After insertion, insertion device 1706 is slid posteriorly, decupling spacer 1702 and plate 1704, 1704′.

Referring to FIGS. 126 and 127 , an alternative embodiment of an intervertebral spacer and plate assembly 1800 (“assembly 1800”) is shown. Assembly 1800 includes a spacer 1802 and a plate 1804. Spacer 1802 includes a body 1810 having a posterior portion 1812. Posterior portion 1812 includes a space 1814 that is sized to receive plate 1804. Plate 1804 can be inserted into space 1814 from a posterior direction or from a superior direction.

Spacer 1802 can include connections for an insertion device (not shown) similar to that disclosed with respect to spacer 102, described above. Assembly 1800 can be inserted as a unit and then, after insertion, the insertion device is removed and spacer 1802 and plate 1804 remain as separate components in the patient's spinal column.

Referring to FIGS. 128-130 an alternative embodiment of an intervertebral spacer and plate assembly 1900 (“assembly 1900”) is shown. Assembly 1900 includes a spacer 1902 and a plate 1904 or plate 1904′. Spacer 1902 includes a body 1910 having a posterior portion 1912. Posterior portion 1912 includes a threaded opening 1914 that is sized to receive an insertion tool (not shown). Each of plates 1904, 1904′ include a threaded connection 1920, 1920′ extending therethrough. Threaded connections 1920, 1920′ accept a threaded insertion device (not shown) that extends though plate 1904, 1904′ and into threaded opening 1914 in plate 1904. The threaded connection between the insertion device and spacer 1902 and plate 1904, 1904′ can be loose to provide for articulation during insertion, similar to the movement of a joystick. Once assembly 1900 is inserted, the insertion device is removed, and spacer 1902 and plate 1904, 1904′ remain as separate components in the patient's spinal column.

FIG. 131 is a top perspective view of a spacer and plate assembly according to a nineteenth embodiment. The spacer and plate assembly 2000 comprises a spacer 2002 and a plate 2004. The spacer 2002 and plate 2004 are advantageously configured to be delivered to a surgical site via an insertion tool. In the present embodiment, the insertion tool comprises a threaded coupling shaft 2070 (shown in FIG. 136 ) that holds both the spacer 2002 and the plate 2004 thereon. Once delivered, the insertion tool can be removed, thereby leaving the spacer 2002 and plate 2004 in place. At the surgical site, the spacer 2002 and plate 2004 are left decoupled and unfixed to one another.

The spacer 2002 comprises a body 2008 having a superior surface 2010 and an inferior surface 2012, each having one or more fixation elements 2014 in the form of protrusions, pyramids, or ribbing. The one or more fixation elements 2014 advantageously serve to grip bone in an adjacent vertebral body. The body 2008 of the spacer 2002 comprises an anterior portion 2020 and a posterior portion 2022 separated by lateral sides 2016, 2018. In some embodiments, the body 2008 comprises a c-shape, wherein the lateral sides 2016, 2018 form curved arms that surround an inner space 2023 for receiving graft material therein. The inner spacer 2023 is surrounded by an inner wall or surface 2027 that curves along an interior of the spacer 2002.

As shown in FIG. 131 , a bore 2026 is formed along the inner surface 2027. In some embodiments, the bore 2026 is a threaded bore. The threaded bore 2026 is configured to receive a threaded distal end 2072 of a coupling shaft 2070 of an insertion tool (shown in FIG. 136 ). In some embodiments, the threaded bore 2026 extends from the inner surface 2027 completely though the anterior portion 2020 of the spacer 2002, while in other embodiments, the threaded bore 2026 extends from the inner surface 2027 only partially through the anterior portion 2020 of the spacer 2002.

As shown in FIG. 131 , the body 2008 of the spacer 2002 includes first and second recesses or indentations 2017, 2019. Indentation 2017 is formed along lateral side 2016, while indentation 2019 is formed along lateral side 2018. The indentations 2017, 2019 serve to receive fingers 2038, 2040 of the plate 2004, as shown in FIG. 136 . The indentations 2017, 2019 advantageously help to stabilize the spacer 2002 and plate 2004 relative to one another when they are operatively coupled via the insertion tool. The spacer 2002 can be formed of both synthetic and natural material. In some embodiments, the spacer 2002 is formed of bone, PEEK or titanium.

The plate 2004 comprises a body 2030 having a superior surface 2032 and an inferior surface 2034. Portions of the superior surface 2032 and inferior surface 2034 include stabilizer elements 2036. In some embodiments, the stabilizer elements comprise protrusions, pyramids, or ribbing that are advantageously designed to provide torsional stabilization.

The plate 2004 further comprises a posterior portion comprising through-holes 2064, 2066, 2068 for receiving fasteners therein. In the present embodiment, the plate 2004 further includes locking screws 2070, 2072, 2074, each associated with one of the through-holes 2064, 2066, 2068. The locking screws 2070, 2072, 2074 each have cut-away regions that allow for entry or removal of fasteners through the plate 2004 in one configuration, but prevent backout of the fasteners when rotated into a second configuration. In some embodiments, the plate 2004 further comprises a pair of non-threaded bores 2044, 2046, each of different sizes. Non-threaded bore 2044 is configured to receive extension 2063 of insertion tool 2006 (shown in FIG. 140A), while non-threaded bore 2044 is configured to receive coupling shaft 2070 of insertion tool 2006 (also shown in FIG. 140A). Non-threaded bore 2044 comprises a partial bore that is not fully enclosed. Non-threaded bore 2044 borders through-hole 2064. Non-threaded bore 2046 comprises a full bore that is fully enclosed. In some embodiments, non-threaded bore 2046 comprises a square, while in other embodiments, non-threaded bore 2046 comprises a square with rounded corners or edges.

The plate 2004 further comprises a pair of arms or fingers 2038, 2040 extending from the posterior portion of the plate 2004. The fingers 2038, 2040 comprise extensions that are configured to be received in the indentations 2017, 2019 of the spacer 2002 when the insertion tool 2006 holds them together. In some embodiments, the fingers 2038, 2040 are configured to include stabilizer elements 2036 thereon. Advantageously, the fingers 2038, 2040 of the plate 2004 are configured to abut surfaces of the spacer 2002 without tightly gripping the spacer 2002, thereby allowing the spacer 2002 to be decoupled from the plate 2004 upon delivery to a surgical site. By providing a decoupled plate 2004 and spacer 2002, each can advantageously be delivered on their own, or together via an insertion tool. In some embodiments, the plate 2004 further comprises windows 2039, which are formed on each of the fingers 2038, 2040. The windows 2039 advantageously provide surgeons openings for visualization, so that they can confirm fusion is taking place.

FIG. 132 is a top view of the assembly shown in FIG. 131 . From this view, one can see the contours of the spacer 2002 and plate 2004. In some embodiments, the spacer 2002 comprises a c-shaped member having a space 2023 for receiving graft material therein. In some embodiments, the plate 2004 comprises fingers 2038, 2040 configured to be received in indentations 2017, 2019 of the spacer 2002. As shown in FIG. 132 , the fingers 2038, 2040 have rounded edges that are configured to abut surfaces of the spacer 2002.

FIG. 133 is a side view of the assembly shown in FIG. 131 . From this view, one can the side contours of the spacer 2002 and plate 2004. In some embodiments, the spacer 2002 comprises one or more chamfers 2029 that allow for clearance of bone fasteners or screws that are inserted through the plate 2004. In some embodiments, the spacer 2002 comprises a pair of chamfers 2029, one found on each of the lateral sides 2016, 2018 of the spacer 2002. In some embodiments, the plate 2004 comprises one or more windows 2039 that provide for visualization. In some embodiments, the windows 2039 are circular. In other embodiments, the windows 2039 are non-rounded, such as square or rectangular.

FIG. 134 is a posterior view of the assembly shown in FIG. 131 . From this view, one can see the through-holes 2064, 2066, 2068 formed in the plate 2004 for receiving bone fasteners or screws therein. In some embodiments, the through-holes 2064, 2066 are configured to receive bone fasteners in a downward direction, while through-hole 2068 is configured to receive a bone fastener in an upward direction. Each of the through-holes 2064, 2066, 2068 is associated with a locking screw 2070, 2072, 2074 with cut-away regions. In some embodiments, locking screws 2070, 2074 are positioned adjacent non-threaded bore 2044, while locking screw 2072 is positioned adjacent non-threaded bore 2046.

FIG. 135 is a posterior view of the spacer shown in FIG. 131 . The spacer 2002 comprises an inner curved wall 2027 that forms a perimeter around inner space 2023. Along the inner wall 2023 is formed a threaded bore 2026 for receiving a coupling shaft 2070 of an insertion tool 2006 (shown in FIG. 136 ).

FIG. 136 is a top perspective view of the assembly shown in FIG. 131 attached to an insertion tool. In the present figure, the insertion tool 2006 is provided with break lines to show internal details. One skilled in the art will appreciate that the insertion tool 2006 does not have such break lines in operation, and that the break lines are to aid in the description of the insertion tool 2006. The insertion tool 2006 comprises an outer shaft 2060 that is coupled to an abutting end 2062 on one end and a handle 2065 on the other end.

The outer shaft 2060 comprises a hollow interior that is configured to receive a coupling shaft 2070 therein. The coupling shaft 2070 comprises a shaft having a threaded distal end 2072. The coupling shaft 2070 is configured to extend through the non-threaded bore 2046 in the plate 2004 (shown in FIG. 131 ) before extending through the threaded bore 2026 of the spacer 2002 (also shown in FIG. 131 ). The coupling shaft 2070 advantageously operatively couples the spacer 2002 and plate 2004 during delivery to a surgical site. In some embodiments, the coupling shaft 2070 can be received in a proximal opening 2068 of the insertion tool 2006, as shown in FIG. 136 . A driver (e.g., a hex driver) can be used to rotate the coupling shaft 2070. This rotation allows the coupling shaft 2070 to threadingly mate with the threaded bore 2026 of the spacer 2002.

The abutting end 2062 of the insertion tool 2006 comprises a distal end of the insertion tool 2006. The abutting end 2062 of the insertion tool 2006 is capable of abutting the plate 2004. As shown in FIG. 140B, extension 2063 and coupling shaft 2070 can extend outwardly from the abutting end 2062.

The handle 2065 of the insertion tool 2006 comprises a gripping surface. A surgeon is capable of gripping the handle 2065 and rotating the coupling shaft 2070 within the insertion tool 2006. In some embodiments, the handle 2065 comprises a proximal opening 2068 for receiving the coupling shaft 2070 therethrough.

FIG. 137 is a top view of the assembly shown in FIG. 131 attached to an insertion tool. From this view, one can see how the outer shaft 2060 of the insertion tool 2006 and thus, the coupling shaft 2070, are offset from a middle axis of the spacer 2002 and plate 2004.

FIG. 138 is a side view of the assembly shown in FIG. 131 attached to an insertion tool. From this view, one can see how the spacer 2002 and plate 2004 are inserted into a surgical site. The spacer 2002 comprises a tapered leading end that aids in insertion of the assembly.

FIG. 139 is a bottom view of the assembly shown in FIG. 131 attached to an insertion tool. From this view, one can see how the spacer 2002 is chamfered on each of its lateral sides 2016, 2018, thereby providing clearance for bone screws or fasteners that are inserted through the plate 2004.

FIGS. 140A-140C illustrate the insertion tool being attached to the spacer and plate assembly in accordance with some embodiments. FIG. 140A illustrates the insertion tool 2006 prior to insertion of the coupling shaft 2070 in the outer shaft 206. FIG. 140B illustrates the insertion tool 2006 with the coupling shaft 2070 inserted in the outer shaft 206. In the present figure, the insertion tool 2006 is not yet engaged with the plate 2004 or spacer 2002. FIG. 140C illustrates the insertion tool 2006 engaged with the plate 2004 via the coupling shaft 2070, but not yet engaged with the spacer 2002. While not shown in FIGS. 140A-140C, the threaded distal end 2072 of the coupling shaft 2070 will engage the threaded bore 2026 of the spacer 2002, thereby operatively coupling the spacer 2002 and plate 2004 during delivery to a disc space. Once delivered, bone fasteners can be inserted into the plate 2004 to thereby fix the plate 2004 to one or more adjacent vertebrae. The insertion tool 2006 can then be removed. Upon removal of the insertion tool 2006, the plate 2004 and spacer 2002 are left in the surgical site, uncoupled to one another.

FIG. 141 is a top perspective view of a spacer and plate assembly according to a twentieth embodiment. The spacer and plate assembly 2100 comprises a plate 2104 having novel gripping components 2142 that are designed to have a first “neutral” configuration whereby a spacer 2102 is ungripped and a second “non-neutral” configuration whereby a spacer 2102 is gripped. While in this second configuration, an insertion tool can advantageously deliver the spacer 2102 and plate 2104 together into a surgical site. Once at the surgical site, the spacer 2102 and plate 2104 can be decoupled by changing the gripping components 2142 back to the first neutral configuration.

The spacer and plate assembly 2100 comprises a spacer 2102 and a plate 2104. The spacer 2102 comprises a body 2108 having a superior surface 2110 and an inferior surface 2112, each having one or more fixation elements 2114 in the form of protrusions, pyramids, or ribbing. The one or more fixation elements 2114 advantageously serve to grip bone in an adjacent vertebral body. The body 2108 of the spacer 2102 comprises an anterior portion 2120 and a posterior portion 2122 separated by lateral sides 2116, 2118. In the present embodiment, the body 2108 comprises an enclosed d-shape, wherein the lateral sides 2116, 2118 form curved arms that surround an inner space 2123 for receiving graft material therein. The inner spacer 2123 is surrounded by an inner wall or surface 2127 that curves along an interior of the spacer 2102.

As shown in FIG. 131 , the body 2108 of the spacer 2102 includes first and second recesses or indentations 2117, 2119. Indentation 2117 is formed along lateral side 2116, while indentation 2119 is formed along lateral side 2118. The indentations 2117, 2119 serve to receive fingers 2138, 2140 of the plate 2104, as shown in FIG. 142 . The indentations 2117, 2119 advantageously help to stabilize the spacer 2102 and plate 2104 relative to one another when they are operatively coupled via the insertion tool. The spacer 2102 can be formed of both synthetic and natural material. In some embodiments, the spacer 2102 is formed of bone, PEEK or titanium.

The plate 2104 comprises a body 2130 having a superior surface 2132 and an inferior surface 2134. Portions of the superior surface 2132 and inferior surface 2134 include stabilizer elements 2136. In some embodiments, the stabilizer elements comprise protrusions, pyramids, or ribbing that are advantageously designed to provide torsional stabilization.

The plate 2104 further comprises a posterior portion comprising through-holes 2164, 2166, 2168 for receiving fasteners therein. In the present embodiment, the plate 2104 further includes locking screws that are received in openings 2171, 2173. The locking screws each have cut-away regions that allow for entry or removal of fasteners through the plate 2104 in one configuration, but prevent backout of fasteners when rotated into a second configuration. In some embodiments, the posterior portion of the plate 2104 comprises recesses 2145, 2147 that are configured to receive gripping components 2140, 2142 therein. The gripping components 2140, 2142 comprise c-shaped bodies having slots 2144, 2146 formed therein. The slots 2144, 2146 enable to the gripping components 2140, 2142 to be compressed and received in the recesses 2145, 2147. The gripping components 2140, 2142 are capable of being in a neutral configuration (shown in FIG. 146A), whereby the spacer 2102 is not compressed. The gripping components 2140, 2142 are further capable of being in a non-neutral configuration (shown in FIG. 147A), whereby the spacer 2102 is compressed. In the neutral configuration, the plate 2104 is not coupled to the spacer 2102, while in the non-neutral configuration, the plate 2104 is coupled to the spacer 2102. Accordingly, by providing these configurations, a surgeon can advantageously choose to deliver the spacer 2102 and plate 2104 to a surgical site together or separately one at a time, depending on the needs of a patient.

One or more holders, instruments or tools can move the gripping components 2140, 2142 from a neutral configuration to a non-neutral configuration. In some embodiments, the gripping components 2140, 2142 permit the plate 2104 to grip the spacer 2102 temporarily. In some embodiments, a single holder or insertion tool can be inserted into the spaces 2147, 2149 adjacent the gripping components 2140, 2142 (shown in FIGS. 146A and 147A), thereby moving the gripping components 2140, 2142 into a non-neutral configuration. In the non-neutral configuration, the gripping components 2140, 2142 of the plate 2104 apply compression on the spacer 2102, thereby temporarily coupling the plate 2104 to the spacer 2102. With the plate 2104 temporarily coupled to the spacer 2102, the insertion tool can deliver the plate 2104 and spacer 2102 to a surgical site. One or more bone fasteners can be inserted into the plate 2104 to attach the plate 2104 to one or more adjacent vertebrae. With the plate 2104 and spacer 2102 in the surgical site, the insertion tool can be retracted from the spaces 2147, 2149, thereby allowing the gripping components 2140, 2142 to spring back into the neutral position. With the gripping components 2140, 2142 in the neutral position, the plate 2104 is no longer coupled to the spacer 2102.

The plate 2104 further comprises a pair of arms or fingers 2138, 2140 extending from the posterior portion of the plate 2104. The fingers 2138, 2140 comprise extensions that are configured to be received in the indentations 2117, 2119 of the spacer 2102. In some embodiments, the fingers 2138, 2140 are configured to include stabilizer elements 2136 thereon. Advantageously, the fingers 2138, 2140 of the plate 2104 are configured to abut surfaces of the spacer 2102 without tightly gripping the spacer 2102, thereby allowing the spacer 2102 to be decoupled from the plate 2104 if desired upon delivery to a surgical site. By providing a decoupled plate 2104 and spacer 2102, each can advantageously be delivered on their own, or together via one or more insertion tools.

FIG. 142 is a top view of the assembly shown in FIG. 141 . From this view, one can see how the inner space 2123 of the spacer 2102 is completed enclosed by the inner wall 2127 of the spacer 2102. In some embodiments, only a single through hole 2168 is upwardly angled.

FIG. 143 is a side view of the assembly shown in FIG. 141 . From this view, one can see how the gripping components 2140, 2142 are capable of being received in the recesses 2145, 2147 formed in the plate 2104. In some embodiments, the gripping components 2140, 2142 are capable of being snapped into the plate 2104.

FIG. 144 is a bottom view of the assembly shown in FIG. 141 . As shown in the figure, a pair of through holes 2164, 2166 are downwardly angled.

FIG. 145 is a posterior view of the assembly shown in FIG. 141 . From this view, one can see each of the through holes 2164, 2166, 2168 for receiving bone screws or fasteners, as well as the locking screws 2170, 2172 that help prevent back out of bone screws or fasteners from the through holes 2164, 2166, 2168. In some embodiments, locking screw 2170 is adjacent through holes 2164, 2168, while locking screw 2172 is adjacent through holes 2166, 2168.

FIGS. 146A-146C illustrate the spacer and plate assembly with the gripping features of the plate in a neutral position in accordance with some embodiments. In the neutral position, the gripping components 2140, 2142 of the plate 2104 are generally parallel to one another and do not compress the spacer 2102. In this position, the plate 2104 and spacer 2102 are considered decoupled from one another. To move the gripping components 2140, 2142 into a non-neutral or compressed position, a holder or instrument is inserted into the recesses 2147, 2149 in the plate. The instrument is designed to press against the angled back surfaces of the gripping components 2140, 2142, which causes then to angle and compress the spacer 2102.

FIGS. 147A-147C illustrate the spacer and plate assembly with the gripping features of the plate in a compressed position in accordance with some embodiments. In this non-neutral configuration, the plate 2104 and spacer 2102 are considered temporarily coupled to one another. To move the gripping components 2140, 2142 back to its neutral position, a holder or instrument simply needs to be retracted. A built in spring force will bring the gripping components 2140, 2142 back to the neutral position.

FIG. 148 is a top perspective view of a spacer and plate assembly according to a twenty-first embodiment. The spacer and plate assembly 2200 comprises a spacer 2202 and a plate 2204. The spacer 2202 and plate 2204 are configured to be delivered to a surgical site, for example, via an insertion tool 2206 (shown in FIG. 153 ). In the present embodiment, the insertion tool 2206 comprises a holder 2270 (shown in FIGS. 153-160 ) that holds both the spacer 2202 and the plate 2204 thereon. Once delivered, the insertion tool can be removed, thereby leaving the spacer 2202 and the plate 2204 in place. At the surgical site, the spacer 2202 and plate 2204 may be left decoupled and unfixed to one another.

The spacer 2202 comprises a body 2208 extending along a central longitudinal axis 2209 and having a superior surface 2210 and an inferior surface 2212, each having one or more fixation elements 2214 in the form of protrusions, pyramids, teeth, ribbing, or other texture. The one or more fixation elements 2214 serve to grip bone in an adjacent vertebral body. The body 2208 of the spacer 2202 comprises an anterior portion 2220 and a posterior portion 2222 separated by first and second lateral sides 2216, 2218. The first lateral side 2216 extends along a first side of the longitudinal axis 2209, while the second lateral side 2218 extends along an opposing side of the longitudinal axis 2209.

In some embodiments, the body 2208 comprises a “C” shape, wherein the lateral sides 2216, 2218 form curved arms that surround an inner space 2223 for receiving graft material therein. The inner space 2223 is surrounded by an inner wall or surface 2227 that curves along an interior of the spacer 2202.

In some embodiments, the spacer 2202 comprises one or more chamfers 2229 that allow for clearance of bone fasteners or screws that are inserted through the plate 2204. In some embodiments, the spacer 2202 comprises a pair of chamfers 2229, one found on each of the lateral sides 2216, 2218 of the spacer 2002.

The inner surface 2227 along lateral side 2216 includes a prong receiver 2241 that is sized to receive a prong 2294 of the holder 2270 (shown in FIG. 156 ). The prong receiver 2241 is open to the inner space 2223 of the body 2208 of the spacer 2202.

As shown in FIGS. 148-150 , a rod receiver 2226 is formed in the posterior portion 2222 along the lateral side 2218 and extends along an oblique axis 2227 relative to the longitudinal axis 2209. In some embodiments, the rod receiver 2226 is a female threaded bore. In alternative embodiments, the rod receiver 2226 can be a smooth bore, with a separate threaded insert (not shown) inserted into the bore 2226.

The female threaded rod receiver 2226 is configured to receive a male threaded distal end 2274 of a threaded rod 2272 of the holder 2270. While a male and female threaded connection is shown, those skilled in the art will recognize that the male and female connection may be reversed or other types of connections, such as, for example, a quarter turn key-style lock, can be used to secure the rod 2272 to the spacer 2202.

In some embodiments, the threaded rod receiver 2226 extends from the posterior portion 2222 only partially through the lateral side 2218 of the spacer 2202 (e.g., a blind hole). While in other embodiments (not shown), the threaded rod receiver 2226 can extend completely through the anterior portion 2020 of the spacer 2002, and in other embodiments, the threaded bore 2026 extends completely through the lateral side 2218 of the spacer 2202.

As shown in FIG. 150 , the body 2208 of the spacer 2202 includes first and second recesses or indentations 2217, 2219. Indentation 2217 is formed along the lateral side 2216, while indentation 2219 is formed along the lateral side 2218. The indentations 2217, 2219 serve to receive fingers 2238, 2240 of the plate 2204. The indentations 2217, 2219 help to stabilize the spacer 2202 and plate 2204 relative to one another when they are operatively coupled via the holder 2270. Recesses 2260, 2262 in the indentations 2217, 2219, respectively, extend anteriorly from posterior portion 2222 toward the anterior portion 2220. The recesses 2260, 2262 are sized to accept prongs (not shown) on the plate 2204 to stabilize the connection between the spacer 2202 and the plate 2204. The spacer 2202 and plate 2204 can be formed of suitable biocompatible materials, including synthetic and natural materials. In some embodiments, the spacer 2202 is formed of bone, PEEK or titanium, and the plate 2204 is formed of titanium.

The plate 2204 comprises a body 2230 having a superior surface 2232 and an inferior surface 2234. Portions of the superior surface 2232 and inferior surface 2234 may include stabilizer elements 2236. In some embodiments, the stabilizer elements may comprise protrusions, pyramids, or ribbing that are designed to provide torsional stabilization.

The plate 2204 further comprises a posterior portion comprising through-holes 2264, 2266, 2268 for receiving fasteners therein. In the present embodiment, the plate 2204 further includes locking screws 2271, 2273, 2275, each associated with one of the through-holes 2264, 2266, 2268. The locking screws 2271, 2273, 2275 each have cut-away regions that allow for entry or removal of fasteners through the plate 2204 in one configuration, but prevent backout of the fasteners when rotated into a second configuration. In some embodiments, the plate 2204 further comprises a pair of non-threaded bores 2244, 2246, each of different sizes. Non-threaded bore 2244 extends fully through the plate 2204 and is configured to allow the prong 2294 of the holder 2270 to pass therethrough and into the prong receiver 2241 in the spacer 2202 (shown in FIG. 156 ), while bore 2246 is a rod opening that is configured to receive the distal end 2274 of the rod 2272 and allow the distal end 2274 of the rod 2272 to pass therethrough and into the spacer 2202 (shown in FIG. 156 ). Non-threaded bore 2244 is a prong opening that borders through-hole 2264. In some embodiments, the non-threaded bores 2244, 2246 each comprises a square, while in other embodiments, the non-threaded bores 2244, 2246 each comprises a square with rounded corners or edges or, alternatively, can be other shapes, such as triangular, pentagonal, hexagonal, and the like. Both bores 2244, 2246 extend along an axis 2227 that is oblique to the longitudinal axis 2209 so that the rod 2272 in the holder 2270 can pass through the holder 2270 and engage both the plate 2204 and the spacer 2202 without interfering with or obstructing any graft material inserted into the inner space 2223.

The plate 2204 further comprises a pair of arms or fingers 2238, 2240 extending from the posterior portion of the plate 2204. The fingers 2238, 2240 comprise extensions that are configured to be received in the indentations 2217, 2219 of the spacer 2202 when the holder 2270 holds them together. Advantageously, the fingers 2238, 2240 of the plate 2204 are configured to abut surfaces of the spacer 2202 without tightly gripping the spacer 2202, thereby allowing the spacer 2202 to be decoupled from the plate 2204 upon delivery to a surgical site. By providing a decoupled plate 2204 and spacer 2202, each can advantageously be delivered on their own, or together via an insertion tool, such as the holder 2270. The fingers 2238, 2240 provide stability when the plate 2204 is used without the spacer 2202.

FIG. 149 is a posterior view of the assembly shown in FIG. 148 . From this view, one can see the through-holes 2264, 2266, 2268 formed in the plate 2204 for receiving bone fasteners or screws therein. In some embodiments, the through-holes 2264, 2266 are configured to receive bone fasteners in a downward direction, while through-hole 2268 is configured to receive a bone fastener in an upward direction.

FIG. 153 is a top perspective view of the assembly shown in FIG. 148 attached to the insertion tool 2206. The insertion tool 2006 comprises the holder 2270 and the rod 2272. The holder 2270 includes a holder body 2280 having a proximal end 2282, a distal end 2284 having a plate engaging surface 2286, a mid portion 2290 disposed between the proximal end 2282 and the distal end 2284, and a channel 2292 extending through the holder 2270 between the proximal end 2282 and the distal end 2284.

The proximal end 2282 of the holder 2270 has a first width and the mid portion 2290 of the holder 2270 has a second width, less than the first width such that the mid portion 2290 extends wholly on one side of the longitudinal axis 2209, as shown in FIG. 154 . The size and location of the mid portion 2290 allows a user to grip the holder 2270 and manipulate the holder 2270 during insertion of the assembly 2200.

The channel 2292 has an arcuate, or curved, shape within the distal end 2284 in order for the rod 2272 to be able to curve within the channel 2292 and pass through the rod opening 2246 in the plate 2204. To facilitate formation of the curved portion of the channel 2292, in an exemplary embodiment, the holder 2270 is constructed from an upper portion 2296 and a lower portion 2298 (shown in FIG. 155 ), with the lower portion 2298 being bonded to the upper portion 2296 along a bonding line 2299. The curvature of the channel 2292 has a sufficiently large radius such that the amount of deflection of the rod 2272 is minimized, reducing frictional engagement of the rod 2272 within the channel 2292 as the rod 2272 is inserted through the channel 2292.

A prong 2294 extends distally from the distal end 2284. The prong 2294 is sized to extend through the prong opening 2244 and into the prong receiver 2241 to stabilize the assembly 2200 on the insertion tool 2206 during insertion. A rod opening 2295 is formed at the distal end 2284 and extends along an oblique angle relative to the longitudinal axis 2209 so that the rod opening aligns with the rod opening 2246 in the plate 2204, allowing the rod 2272 to be inserted through the channel 2292 and the rod opening 2246, and into the rod receiver 2226.

The rod distal end 2274 is sized to be inserted into the proximal end 2282 of the holder 2270, through the channel 2292 in the holder body 2270, through the rod opening 2246 in the plate 2204 and into the spacer 2202 such that the distal end 2274 releasably engages the rod receiver 2226. The rod 2272 may be constructed from an elastic metal such as, for example, Nitinol, which allows the rod 2272 to bend as the rod 2272 is advanced through the channel 2292.

Optionally, although not shown, the holder 2270 can also include channels for anchors, as well as openings for screws to pass through for securing the plate 2204 to vertebrae (not shown).

The holder 2270 advantageously operatively couples the spacer 2202 and plate 2204 during delivery to a surgical site. The engaging surface 2286 of the distal end 2284 of the holder 2270 abuts the plate 2204 so that the assembly 2200 is securely connected to the insertion tool 2206.

FIG. 154 is a top view of the assembly 2200 shown in FIG. 148 attached to the insertion tool 2206. From this view, one can see how the mid portion 2290 of the holder 2270 is offset from the longitudinal axis 2209 of the assembly 2200.

FIG. 155 is a side view of the assembly 2200 shown in FIG. 148 attached to the insertion tool 2206. From this view, one can see how the spacer 2202 and plate 2204 are inserted into a surgical site. The spacer 2202 comprises a tapered leading end that aids in insertion of the assembly 2200.

FIGS. 157-160 illustrate the insertion tool 2206 being attached to the spacer and plate assembly 2200 in accordance with some embodiments. FIG. 157 illustrates the holder 2270 prior to insertion of the rod 2272 into the channel 2292. FIG. 158 illustrates the insertion tool 2006 fully assembled with the rod 22732 having been inserted into the holder 2270. FIG. 159 illustrates the insertion tool 2206 engaged with the plate 2204, but not yet engaged with the spacer 2202. FIG. 160 illustrates the spacer 2202 engaged with the holder 2270, with the threaded distal end 2274 of the rod 2272 engaging the threaded bore 2226 of the spacer 2202, thereby operatively coupling the spacer 2202 and plate 2204 during delivery to a disc space.

Once delivered, the insertion tool 2206 can then be removed from the assembly 2200 by unthreading the rod 2272 from the spacer 2202 and removing the insertion tool 2206. Next, bone fasteners can be inserted into the plate 2204 to thereby fix the plate 2204 to one or more adjacent vertebrae. The plate 2004 and spacer 2002 may be left in the surgical site, uncoupled to one another.

All of spacers 102-2202 described above can be constructed from biocompatible material, such as, for example, bone, PEEK, titanium, with or without surface treatments, and with varying porosity.

In some embodiments, any of the plates and spacers described above can be accompanied by other surgical implants, including rods and screws. One of skill in the art will appreciate that any of the plates and spacers can be used on multiple levels of the spine.

It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims. 

What is claimed is:
 1. A spacer assembly extending along a longitudinal axis, the assembly comprising: a spacer having: a body having a first lateral side extending on one side of the longitudinal axis and a second lateral side extending on an opposing side of the longitudinal axis, with an inner space formed between the first and second lateral sides and defining a graft chamber; a prong receiver disposed on the first lateral side; and a rod receiver disposed entirely within the second lateral side so as not to decrease the size of the graft chamber; a plate having: a plate body configured to engage the spacer body; a prong opening disposed on and extending through the plate body, and aligned with the prong receiver; and a rod opening extending through the plate body and aligned with the rod receiver; a holder having: a holder body having a proximal end and a distal end adapted to engage the plate, and a channel extending through the holder body; and a prong extending distally from the distal end, the prong sized to extend through the prong opening and into the prong receiver; and a rod having a distal end, the rod being sized to be inserted through the channel in the holder body, through the rod opening in the plate and into the rod receiver such that the distal end releasably engages the rod receiver without reducing the size of the graft chamber.
 2. The spacer assembly of claim 1, wherein the plate body includes a pair of laterally spaced fingers adapted to respectively engage the first and second lateral sides of the spacer body.
 3. The spacer assembly of claim 2, wherein each of the lateral sides includes a recess for receiving at least a portion of the respective finger.
 4. The spacer assembly of claim 1, wherein the plate body includes: first and second through-holes shaped for receiving fasteners for insertion into a first vertebral body; a third through-hole disposed between the first and second through-holes and shaped for receiving a fastener for insertion into a second vertebral body adjacent to the first vertebral body.
 5. The spacer assembly of claim 4, further comprising first, second and third locking screws each arranged near a respective through-hole for preventing backout of the fastener.
 6. The spacer assembly of claim 1, wherein the rod is constructed from an elastic metal.
 7. The spacer assembly of claim 1, wherein the holder is constructed from an upper portion and a lower portion, the lower portion being bonded to the upper portion.
 8. The spacer assembly of claim 1, wherein the prong receiver is open to the inner space.
 9. The spacer assembly of claim 1, wherein the rod receiver comprises a female threaded passage.
 10. The spacer assembly of claim 9, wherein the rod distal end comprises a male thread sized to threadingly engage the female threaded passage.
 11. The spacer assembly of claim 1, wherein when the prong is inserted into the prong receiver and when the rod distal end is inserted into the rod receiver, the spacer is releasably connected to the holder.
 12. A spacer assembly extending along a longitudinal axis, the assembly comprising: a spacer having: a body having a first lateral side extending on one side of the longitudinal axis and a second lateral side extending on an opposing side of the longitudinal axis, with an inner space formed between the first and second lateral sides and defining a graft chamber; a prong recess disposed on the first lateral side; and a rod recess disposed entirely within the second lateral side so as not to decrease the size of the graft chamber; a plate having: a plate body configured to engage the spacer body; first and second fingers adapted to engage the respective first and second lateral sides of the spacer body; a prong opening disposed on and extending through the plate body, and aligned with the prong recess; and a rod opening extending through the plate body and aligned with the rod recess; a holder having: a holder body having a proximal end and a distal end adapted to engage the plate, and a channel extending through the holder body; and a prong extending distally from the distal end, the prong sized to extend through the prong opening and into the prong recess; and a rod having a distal end, the rod being sized to be inserted through the channel in the holder body, through the rod opening in the plate and into the rod recess such that the distal end releasably engages the rod recess without reducing the size of the graft chamber.
 13. The spacer assembly of claim 12, wherein each of the lateral sides includes a recess for receiving at least a portion of the respective finger.
 14. The spacer assembly of claim 12, wherein the plate body includes: first and second through-holes shaped for receiving fasteners for insertion into a first vertebral body; a third through-hole disposed between the first and second through-holes and shaped for receiving a fastener for insertion into a second vertebral body adjacent to the first vertebral body.
 15. The spacer assembly of claim 14, further comprising first, second and third locking screws each arranged near a respective through-hole for preventing backout of the fastener.
 16. The spacer assembly of claim 12, wherein the rod is constructed from an elastic metal.
 17. The spacer assembly of claim 12, wherein the holder is constructed from an upper portion and a lower portion, the lower portion being bonded to the upper portion.
 18. The spacer assembly of claim 12, wherein the prong recess is open to the inner space.
 19. The spacer assembly of claim 12, wherein the rod recess comprises a female threaded passage.
 20. The spacer assembly of claim 19, wherein the rod distal end comprises a male thread sized to threadingly engage the female threaded passage. 